What should a university student do who betrayed herself and stole her friend's money, then swore falsely on the Qur'an, and is now living in anxiety and confusion because of the problems she faces and her guilty conscience?

You have committed two major sins: theft and lying while swearing on the Qur’an. The suffering and problems you are experiencing may be a consequence of these sins. Allah Almighty says: "And whoever turns away from My remembrance - indeed, he will have a difficult life, and We will gather him on the Day of Resurrection blind." You must return what was stolen, or its value if it has been consumed. You must also regret what you have done, cease the disobedience, and resolve not to return to it. There is no need to explicitly tell your friend; it is sufficient to return it indirectly. If you repent, your sins will be removed, and your life will return to what it was.